Bottom Line:
In the last decade the use of field-effect-based devices has become a basic structural element in a new generation of biosensors that allow label-free DNA analysis.In particular, ion sensitive field effect transistors (FET) are the basis for the development of radical new approaches for the specific detection and characterization of DNA due to FETs' greater signal-to-noise ratio, fast measurement capabilities, and possibility to be included in portable instrumentation.This limitation is sometimes considered to be fundamental for FET devices and considerable efforts have been made to develop better architectures.

ABSTRACTIn the last decade the use of field-effect-based devices has become a basic structural element in a new generation of biosensors that allow label-free DNA analysis. In particular, ion sensitive field effect transistors (FET) are the basis for the development of radical new approaches for the specific detection and characterization of DNA due to FETs' greater signal-to-noise ratio, fast measurement capabilities, and possibility to be included in portable instrumentation. Reliable molecular characterization of DNA and/or RNA is vital for disease diagnostics and to follow up alterations in gene expression profiles. FET biosensors may become a relevant tool for molecular diagnostics and at point-of-care. The development of these devices and strategies should be carefully designed, as biomolecular recognition and detection events must occur within the Debye length. This limitation is sometimes considered to be fundamental for FET devices and considerable efforts have been made to develop better architectures. Herein we review the use of field effect sensors for nucleic acid detection strategies-from production and functionalization to integration in molecular diagnostics platforms, with special focus on those that have made their way into the diagnostics lab.

Mentions:
Field effect based-sensors are used as the transducer of biorecognition events (DNA/RNA hybridization) mainly following two main designs: (1) a metal-insulator- semiconductor (MIS) capacitor; and (2) metal-oxide-semiconductor field effect transistor (MOSFET) that have been slightly modified over the years to meet the challenges of integrating biological reactions with electronic devices [7,8]. The MIS capacitor is one of the most simple and useful devices in the study of electronic circuits, whose structure is a semiconductor-insulator interface that serves as a model for the development of sensitive layers and/or materials. The electrolyte-insulator-semiconductor (EIS) capacitor is one of these modified designs and has been broadly applied for biosensing. The EIS structure is identical to that of a MIS capacitor but the gate electrode is replaced by an electrolyte and a reference electrode. The insulator, commonly an oxide, is thus directly exposed to the electrolyte so changes in the solution can affect the oxide surface potential and modulate the device’s response (Figure 1A,B).

Mentions:
Field effect based-sensors are used as the transducer of biorecognition events (DNA/RNA hybridization) mainly following two main designs: (1) a metal-insulator- semiconductor (MIS) capacitor; and (2) metal-oxide-semiconductor field effect transistor (MOSFET) that have been slightly modified over the years to meet the challenges of integrating biological reactions with electronic devices [7,8]. The MIS capacitor is one of the most simple and useful devices in the study of electronic circuits, whose structure is a semiconductor-insulator interface that serves as a model for the development of sensitive layers and/or materials. The electrolyte-insulator-semiconductor (EIS) capacitor is one of these modified designs and has been broadly applied for biosensing. The EIS structure is identical to that of a MIS capacitor but the gate electrode is replaced by an electrolyte and a reference electrode. The insulator, commonly an oxide, is thus directly exposed to the electrolyte so changes in the solution can affect the oxide surface potential and modulate the device’s response (Figure 1A,B).

Bottom Line:
In the last decade the use of field-effect-based devices has become a basic structural element in a new generation of biosensors that allow label-free DNA analysis.In particular, ion sensitive field effect transistors (FET) are the basis for the development of radical new approaches for the specific detection and characterization of DNA due to FETs' greater signal-to-noise ratio, fast measurement capabilities, and possibility to be included in portable instrumentation.This limitation is sometimes considered to be fundamental for FET devices and considerable efforts have been made to develop better architectures.

ABSTRACTIn the last decade the use of field-effect-based devices has become a basic structural element in a new generation of biosensors that allow label-free DNA analysis. In particular, ion sensitive field effect transistors (FET) are the basis for the development of radical new approaches for the specific detection and characterization of DNA due to FETs' greater signal-to-noise ratio, fast measurement capabilities, and possibility to be included in portable instrumentation. Reliable molecular characterization of DNA and/or RNA is vital for disease diagnostics and to follow up alterations in gene expression profiles. FET biosensors may become a relevant tool for molecular diagnostics and at point-of-care. The development of these devices and strategies should be carefully designed, as biomolecular recognition and detection events must occur within the Debye length. This limitation is sometimes considered to be fundamental for FET devices and considerable efforts have been made to develop better architectures. Herein we review the use of field effect sensors for nucleic acid detection strategies-from production and functionalization to integration in molecular diagnostics platforms, with special focus on those that have made their way into the diagnostics lab.